six is the canonical compatibility library for supporting
Python 2 and 3 in a single codebase.
The urlparse module was removed in Python 3 and we should
use 'six.moves.urllib.parse' instead of 'urlparse' to make
code compatible with py 2 and 3 as well.
Partially-implements blueprint py3-compatibility
Change-Id: Ib27244d0583e81e307d5e4236cbf85d29566dde9